This invention relates to a wide-screen television receiver.
That is, if a video signal having a non-wide aspect ratio (for example, 4:3) is received by a television receiver and displayed directly on a wide-screen of an aspect ratio (for example, 16:9), the image of the video signal will be distorted in the lateral direction on the display screen. Thus, in this case, if this video signal is converted into a video signal of a proper aspect ratio before it is displayed on the screen, the video signal of a non-wide aspect ratio can be normally displayed without distortion on the wide screen of a wide aspect ratio. This invention relates to this wide-screen television receiver.
In addition, this invention relates to another wide-screen television receiver having a wide-screen display and capable of enlarging an arbitrary portion of a video image in the horizontal and vertical directions at given magnifications and displaying it on the screen.
Recently, as the television receiver becomes large-sized, it is absolutely necessary to improve the picture quality of the displayed video image. Thus, various high-definition television systems have been proposed and are being practically used. There are known the second-generation EDTV (Extended Definition TV) which has the same number of scan lines and field frequency as those of the present television system (NTSC) and a wide aspect ratio (16:9) for increasing the realism, and the HDTV (High Definition TV) which has a different number of scan frequency and a different field frequency from those of the present television system and which has a wide aspect ratio (16:9). The first-generation EDTV has a non-wide aspect ratio (4:3) as in the prior art.
In the future, the HDTV will be supposed to prevail over the other systems, and at the same time the HDTV system and the present television system which have different aspect ratios will be expected to coexist for a while. Therefore, the future television receiver will have a wide-screen display of aspect ratio, 16:9.
Thus, the video signal of aspect ratio 4:3 used at present is necessary to be displayed on a wide-screen display of aspect ratio 16:9. The displaying method is disclosed in, for example, JP-A-1-194783.
According to JP-A-1-194783, when a video signal of aspect ratio 4:3 as shown in FIG. 25A (a1) is received and directly displayed on a wide screen of aspect ratio 16:9, it is displayed to be long in the horizontal direction as shown in FIG. 25A (a2). Thus, the video signal is compressed in the horizontal direction by use of a memory and displayed together with additional left and right frames as shown in FIG. 25A (a3) or it is magnified and displayed with upper and lower parts cut off on the wide screen of aspect ratio 16:9.
Moreover, when a lateral-long video signal with blanks inserted such as movie software is received, compressed in the horizontal direction and displayed, it becomes small at the central area on the wide screen of aspect ratio 16:9 as shown in FIG. 25B (b2). Thus, the utilization efficiency of the screen is poor and the realism is lost. Therefore, the lateral-long image is magnified up to the upper and lower limits of the wide screen of aspect ratio 16:9 and displayed thereon as shown in FIG. 25B (b3).
Thus, the wide-screen television receiver having a wide-screen display is able to receive not only the wide video signal of aspect ratio 16:9 but also the non-wide video signal of aspect ratio 4:3, and convert the non-wide aspect ratio into a ratio suitable for the wide-screen display so that the video signals of different aspect ratios can be displayed with no distortion.
In addition, when the input video signal is laterally long with a blank inserted on the upper and lower sides as is the movie software video, the video portion is magnified by the above-mentioned method so as to be displayed all over the wide screen. Thus, the video signal is processed by various ways so that it can be displayed with realism over the entire area of the wide screen.